Abrasive element



Oct. 3, 1933.

ABRAS I VE ELEMENT Filed July 18, 1929 INVENTOR. cffZ/r'am $63726 ATTORNEYS w. J. ELLIS 1,929,274-

Patented Oct. 3, 1933 a ABRASIVE ELEMENT William J. Ellis, Cleveland,Ohio Application: July 18, 1920. i Serial No. 379,240

3 Claims.

to an abrasive element, is particularly directed to a tubular, abrasiveelement or so-called sleeve and to a new improved and more economical 5method of manufacturing the same. The principal object of the inventionis the provision of a simple and inexpensive sleeve and the method ofmaking same which shall be very much moresimple and shall at the sametime produce a very much stronger sleeve than those now. in

general use.

To the accomplishment of the foregoing and related ends, said invention,then, consists of the means and steps hereinafter fully described 1 andparticularly pointed out in the claims; the annexed drawing and thefollowing description setting forth in detail certain means and one modeof carrying out the invention, such disclosed means and modeillustrating, however, but one of various ways in which the principle ofthe invention may be used.

In said annexed drawing:-

Pig. lis a view in perspective of my improved 1 abrasive element; Fig. 2is a plan'viewof a sleeve of abrasive coated fabric for use in makingthe sleeve of Fig. 1; Fig. 3 is a section on the line 33. Fig. 2; Fig. 4is a side elevation of a formed 7 sleeve; and Fig. 5 is a view inperspective of a' modification of my improved sleeve. 3 An abrasivesleeve consists of a hollow tubular element formed of a layer ofsuitable support-. ing material, such for example as fabric or some kindof paper stock, the outer surface of which is coated with an adhesiveand a layer of abrasive. These sleeves are putto numerous uses,

being formed in various sizes and being. employed insurfacing convexportionsof metal and woodpanels. castings and the like, while smallersleeves re used for. many other purposes, such for exi0 ample as thegrinding down of very small castings of precious and semi-preciousmetals and for the finishing of small objects of porcelain or similarmaterials.

My improved sleeve consists, briefly stated. of

415 a spirally wrapped sheet of abrasively coated maas applied over aportion of surfacecnly, ex-

adjacentedgosorsidesof' The present invention, relating, as indicated,

tending from the edge 5 to a line 6 parallel with the edges 5 and 7 ofthe strip. It is immaterial as to whether the uncoated portion 8 of thestrip 1 is first coated with abrasive and the abrasive then removed oris in some way left uncoated during the coating operation applied to theini-- tial sheet.

I'he strip 1 I then wrap spirally upon itself, this operation beingperformed either manually v or by suitable machines in such a way as tocause W the coated portion of the sheetto overlap and engage against theportion of the sheet 8. The process is substantially that' of twisting apaper strip about itself to form a spiral tube. except that the coatedabra'sivestrip is here so wrapped that itengages'only over the uncoatedportion of the sheet, thus providing a substantially smooth unbrokensurface of abrasive on the outer surface of the resulting tube.

In Fig 4 I have shown the abrasive strip 1 so wrapped upon itself as toproduce a spirally extending Joint 10 between the adjacent abrasivelayers 11 and 12. The portion 12 engages upon the uncoated portion 15.0!the next convolution of material, and by spreading a suitable layer of.adhesive upon this uncoated portion of the strip before the latter is,thus wound, it is possible to produce a integral spirally wound tube'which may be cut into cylindrical sleeves 18, i7, 1;, etc., of anydesired In Fig. 5 I have a modification of the sleeve previouslydescribed, this modification consisting in the use of a hollow tubularsupporting mandrei-m-within the sleeveproper. The use of this mandrel,while not necessary, is sometimes an advantage, both manufacture of thesleeve and also in its use.- In manufacturing thesleeveitis'ofcoursenecessarytousesome sort of a removable mandrel onwhich to roll up the 06- abrasive strip, and if the permanent mandrel 20is employed it can be used in long lengths, about which the strip canthen be coiled and can be conveniently cut of! at time as the strip.

The mandrel may be formed of paper, cardboard loo or similar inexpensivematerial. A further advantage in the manufacture of the sleeve with theuse of the mandrel is that the uncoated edge portion 8 of the strip 1may then be omitted, the

abrasive strip being coiled spirally about the man:- 106sleeveisusedonanexpandingmandrejlofthello" usual type the ends of thesleeve are expanded more than the central portion, producing a convexsurface from end to end of the sleeve instead of a perfectly straightcylindrical surface as desired. With a pasteboard mandrel within thesleeve the expanding pressure is applied against the mandrel instead ofagainst the sleeve proper and no'unequal expansion can occur.

The present sleeve has the advantage over those now manufactured ofhaving a very much stronger joint between the adjoining portions than itis possible to secure in the tongue and grooved joints which are nowcommonly used. This joint is extremely strong and offers no. objectionin use since there is no extending projection or seam at the jointbetween adjoining convolutions. In manufacture, the present methodpresents several advantages, the most important of which is that sleevesmay now be formed continuously in long lengths of stock and by automaticmachinery, after which the resulting long lengths may be cut into anydesired lengths for various uses.

Other forms may be employed embodying the features of my inventioninstead of theone here explained, change being made in the form orconstruction, provided the elements stated by any of the followingclaims or the equivalent of such atafted elements be employed, whetherproduced by my preferred method pr by others embodying steps equivalentto those stated in the following claims. v

I therefore particularly point out and distinctly claim as myinvention:---

1. In a method of making a tubular abrasive element, the steps whichconsist in wrapping spirally upon a hollow mandrel an abrasive coatedstrip with the edges of adjacent convolutions in contact'with eachother, and securing said strip to said mandrel by interposing a layer ofadhesive,

2. In a method of making a tubular abrasive element, the steps whichconsist in wrapping spirally upon a hollowymandrel an abrasive coatedstrip with the edges of adjacent convolutions in contact with eachother, securing said strip to said mandrel by interposing a layer ofadhesive, and then cutting cylindrical blanks from said wrapped mandrel.

3. An abrasive element comprising a hollow cylindrical mandrel and aspirally wrapped abrasive coated sheet adhesively secured to saidmandrel and completely covering the outer surface thereof, theconvolutions of said sheet having adjacent edges in contact withoutoverflowing.

- WILLIAM'J. ELLIS.

